The use of an elongated tubular instrument for insertion into a surgical site is known and such instruments have been used in performing microsurgical operations within eyes and other internal portions of a patient. In such microsurgical operations it is frequently necessary to cut materials within the surgery site and the need for very small scissor action surgical instruments for performing such cutting have been needed. One such scissor action apparatus is shown in H. de Laforcade U.S. Pat. No. 4,877,026, issued Oct. 31, 1989 for Surgical Apparatus. That patent lists several patents stated to be exemplified of the state of the art for microsurgical instruments.
The elongated tubular members of microsurgical instruments that are inserted into the surgical site are used to transfer motion from motion producing elements outside of the surgical site to elements that are within the surgical site. It becomes necessary for successful useage of the instruments that the moving elements at the end of the elongated tubular member within the surgical site accomplish their movements in a smooth and controlled manner and with a minimum of undesirable or uncontrolled movements. Accomplishing the control of the moving elements and the reduction of motion resistance through the elongated tubular member has been the objective of many developments in the microsurgical instruments.
In scissor action cutting elements functioning at the end of an elongated tubular member where two cutting surfaces are moved with respect to each other it becomes desirable to cause the scissor cutting surfaces to move in a smooth motion and at a substantially uniform cooperating engagement throughout the entire scissor action. Accomplishing those desires at the free end of an elongated tubular microsurgery element becomes difficult.
Accordingly, one object of the present invention is the provision of a microsurgical apparatus having scissor action cutting elements at the free end of an elongated tubular member adapted to be inserted into a surgery site with motion elements outside of the surgery site for transfering motion through the tubular member to cause the scissor action at the cutting elements within the surgery site.
A further object of the present invention in accord with the preceeding object is an assembly of elements and members in a microsurgical instrument that will permit smooth cutting motion at the scissor action cutting elements within a surgical site.
Another object of the present invention in accord with the preceeding objects is a construction and assembly of elements that will cause the scissor action operating elements at the free end of a tubular element to be firmly pressed against each other.
These and other objects and features of the present invention will be readily apparent to those skilled in the art from the appended drawings and specification illustrating a preferred embodiment wherein: